The present invention relates to a multi-channel data recorder, and more particularly is applicable to a data recorder for recording data from a plurality of channels sequentially.
There is so called digital audio tape recorder (DAT) as a magnetic recording apparatus which makes slanted recording tracks sequentially arranged on a magnetic tape by using rotary heads and records digital audio signals on the recording tracks sequentially.
In such digital audio tape recorder, the audio signals are converted into a digital signal for recording and/or reproducing and effectively avoid tone degradation by means of execution of error correcting procedures.
Recently, by using an integrated circuit, an overall shape can be made compact and light-weight.
It is convenient if various data can be recorded by utilizing this kind of digital audio tape recorder.
Further, in such case, it is possible to record or reproduce the data easily using a construction of digital audio tape recorder and to form a compact and light weight tape recorder so that a signal recording format of this digital audio tape recorder can be utilized effectively.
FIG. 1 illustrates a signal recording mode of a digital audio tape recorder (DAT) to record signals on a tape by using so called rotary heads. In the digital audio tape recorder, two signal recording modes, that is, an SP (standard play) mode and an LP (long play) mode, are performed. In the SP mode, an input signal is able to be recorded as data having 16 bits in one word, 48 [kHz] in sampling frequency and two channels (i.e. L and R channels). In the LP mode, the input signal is able to be recorded with the numbers of the recording channels which are increased by two channels as compared to the SP mode.
FIG. 2 illustrates a standard of data conversion/compression in a case where, in the LP mode, the signal with 16 bits in one word is compressed into a signal with 12 bits in one word and is recorded on the tape. The 8 bits of the signal with 16 bits in one word is extracted corresponding to the amplitude level. Range bits of 4 bits representing the amplitude levels (or ranges) are generated and added to the 8 bits of the signal to record as a signal with 12 bits in one word on the tape. The low-order bits following the 8 bits extracted from the signal with 16 bits in one word are omitted when converting/compressing into 12 bits in one word.